We propose a combined field and laboratory approach investigating cognitive spatial mapping in the blind through virtual navigation and assessing the transference of acquired spatial knowledge in a real-world navigation task. Training and evaluation of navigation performance will be carried out with a user-centered, computer-based navigation software platform called Auditory-based Environment Simulator (AbES). This software was developed to assist in orientation and mobility (O&M) training by introducing a blind user to an unfamiliar environment through immersive virtual navigation. Using auditory spectral cues, a user learns to build a cognitive spatial map of their physical surroundings. In this study, participants will interact with the software and navigate through a simulated virtual environment that represents an actual physical space. In a first phase of the study, we will compare learning and spatial cognitive map development in early and late blind individuals using the software in two different modes: 1) directed navigation of pre-determined routes guided by a facilitator and 2) self-directed (or "open discovery") navigation under the pretext of an exploration-theme video game. The ability to translate acquired spatial information will then be assessed with navigating tasks carried out in the actual physical environment. In a second phase of the study, we will investigate the neural correlates associated with spatial navigation. Using functional magnetic imaging (fMRI), neural networks associated with navigation will be assessed in sighted compared to early and late blind individuals and as a function of overall behavioral performance over time. Secondly, the functional contribution of identified cortical areas will be assessed by reversible cortical disruption using transcranial magnetic stimulation (TMS). The results of this study will 1) contribute new insights towards our understanding of the neural mechanisms associated with navigation and 2) develop novel approaches for orientation and navigation training in the blind. PUBLIC HEALTH RELEVANCE: We propose to investigate cognitive spatial mapping skills in the blind through virtual navigation of real-world environments using a computer-based software approach. The results of this study will contribute new insights towards our understanding of the neural mechanisms associated with navigation and develop novel approaches for orientation and mobility training in the blind.